Quantitative analysis of PET microplastics in environmental model samples using quantitative 1H-NMR spectroscopy: validation of an optimized and consistent sample clean-up method

Sample Preparation Techniques for the Analysis of Microplastics in Soil—A Review

“…PVC recovery was 85% while PS was evaluated qualitatively. In recent years, further technical and analytical developments have lowered recoverable concentrations by a factor of 20-50 [33,121,122] and made a broader spectrum of polymers amendable to extraction. Current methods not only include the commonly used polymers PE, PP, PS, PET, PC, and PMMA [123,124] but also biodegradables like polybutylene sebacate (PBS) and PBAT [125,126].…”

“…This may be circumvented by precipitating the polymers in an inert matrix such as quartz sand for further sample processing [122]. Less selective extraction conditions may cause interferences from co-extracted matrix constituents [33], which need to be tackled by additional clean-up steps with methanol, Fenton oxidation, or density separation prior to polymer extraction [121,122]. In this respect, soil is a particularly challenging matrix for its diverse and heterogeneous nature.…”

Applicable and cost‐efficient microplastic analysis by quantitative 1H‐NMR spectroscopy using benchtop NMR and NoD methods

“…The following acquisition parameters have been used: for PET in CHCl 3 /TFA 4:1, spectral width 5 kHz, number of scans 128, number of points 16,384, saturation period 2 s, saturation power À65 dB, acquisition time 3.2 s, flip angle 90 , repetition time 10 s, and measurement time 21.67 min. All low-field 1 H-NMR measurements were performed with the use of 13 C WALTZ decoupling.…”

“…[6,11] On this basis, we have successfully introduced quantitative 1 H-NMR (qNMR) spectroscopy as a new mass-based MP quantification method. [12][13][14] The high accuracy and low error proneness of qNMR in the identification and quantification of MP particles (low-density polyethylene [LDPE], polyethylene terephthalate [PET], polystyrene [PS], polyvinylchloride [PVC], acrylonitrilebutadiene-styrene [ABS], and polyamide 6.6 [PA]), as our preliminary work has shown, clearly raise the question of further developing this method into a routinely applicable analytical technique. [12,14] This approach seems to be promising due to short measurement times (<5 min per measurement) and the method being largely insensitive to environmental matrix effects.…”

“…[12,14] This approach seems to be promising due to short measurement times (<5 min per measurement) and the method being largely insensitive to environmental matrix effects. [13,14] Nevertheless, with regard to the potential application of qNMR methods as a routine analytical technique, cost-efficiency still is a major problem. This was already addressed in the before-mentioned review article by Primpke et al, who mentioned the costs for deuterated solvents as well as the high purchase and operating costs for high-field NMR devices (300-1,000 MHz) as a potential problem.…”